• 한국물환경학회지
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• 제29권6호
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• pp.762-776
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• 2013

Load duration curve was applied to determine important water quality parameter control term for improvement of Paldang lake water quality. Load duration curve was analyzed with long term data from 1985 to 2012 including water quality, flow rate and climate state of Paldang water environment. From the result of flow rate patterns of paldang lake, differences between high and low flow rate of each year showed tendency of increase because rainfall characteristics of paldang lake watershed were changed by climate exchange. Both of land use state of upper Paldang lake watershed and number of limit excess from load duration curve indicated that seasonal action related with land use such as agricultural fertilizer distribution in upper watershed affected Paldang lake water quality. So focused BOD (biological oxygen demand) management during spring season from march to June is required to control organic materials in Paldand lake. The main affecting factor of TOC (total organic carbon) increase in Paldang lake was initial rainfall after march. T-N (total nitrogen) kept increasing during research period, so enhancement of T-N standard is needed to T-N control. Initial rainfall and increase of temperature during spring season from March to June showed a positive correlation with TP (total phosphorus) and Chl-a, respectively.

• 한국안전학회지
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• 제27권5호
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• pp.135-140
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• 2012

In this study, the behavior of pollutant was calculated at Paldang reservior according to several scenarios of the accidental water pollution by means of the numerical models for forecasting water quality. Also managemental plans for situation of the accidental water pollution happening at Paldang watershed were simulated. According to the simulating results, a plan of increase of discharge at Cheongpyeong dam reduced the peak concentration of pollutants, whereas extended the time for stopping water intake. Another plan, drop of water elevation at Paldang dam, decreased seriously the time for stopping water intake although there were a little effect to decrease the peak concentration. Thus it was concluded that appropriate combinations of the plans for the increase discharge and the dropping water elevation should be used to deal with the accidental water pollution at Paldang watershed.

• 한국방재학회 논문집
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• 제10권2호
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• pp.111-122
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• 2010

한강의 잠수교와 둔치는 장마철에 큰 홍수가 발생하면 침수가 되기 때문에 시민들의 안전과 편의를 위해 홍수로 인한 침수 발생시간을 예측하는 것은 대단히 중요하다. 본 연구에서는 FLDWAV모형을 이용하여 한강하류부의 팔당댐 방류량과 황해(서해) 조석이 한강하류부 수위에 미치는 영향을 분석하였다. 연구 대상구간은 팔당댐 하류부에서 전류지점까지이며, 조석영향을 고려하기위해 하류경계조건인 전류수위는 팔당댐방류량과 인천조위를 이용한 다중선형회귀분석을 통해 산정된 예측 전류수위를 사용하였다. 본 연구에서는 잠수교와 주요 둔치에서 수위상승도달시간을 산정하였고, 팔당댐 방류유형과 황해조석에 따른 수위상승도달시간을 팔당댐 방류량의 함수인 2차다항식으로 나타냈다.

• Journal of Ecology and Environment
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• 제32권4호
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• pp.257-265
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• 2009

We estimated monthly and annual secondary productivity of pelagic zooplankton in Lake Paldang and Lake Cheongpyong. Secondary productivity was calculated by combining estimated zooplankton biomass and biomass-specific productivity for each site and depth from March to November 2008. In addition to somatic production, we measured production of eggs and exuviae for three dominant species: Daphnia galeata, Bosmina longirostris, Cyclops sp. In terms of biomass, B. longirostris was dominant in Lake Paldang in April and May, B. longirostris showed explosive biomass growth, especially in May. In June and July, B. longirostris and D. galeata were both dominant. Lake Cheongpyeong showed much lower zooplankton biomass than Lake Paldang. In August, there was little or no biomass in both lakes probably due to heavy rain. The Gyeongan River contributed most of the secondary productivity and B. longirostris contributed the most secondary productivity in Lake Paldang. D. galeata also contributed in the Gyeongan River, the South Han River and at the Paldang Dam in spring and fall. Overall, Lake Cheongpyeong showed lower secondary productivity than Lake Paldang. B. longirostris made the largest contribution to secondary productivity in the Cheongpyeong Dam area while D. galeata contributed the most near Nami Island. Somatic production constituted ~80% of the total secondary productivity (the sum of somatic, egg and exuvia production) for D. galeata and B. longirostris. Although production-to-biomass (P/B) ratios were usually <<1 B. longirostris sometimes showed very high P/B ratios, probably due to fish predation. D. galeata showed much lower P/B ratios than B. longirostris after the summer at most sites.

• 한국물환경학회지
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• 제26권2호
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• pp.311-316
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• 2010

We estimated the nitrogen and phosphorus loads of wintering waterfowl feces in Lake Paldang. The average number of individual birds that belonged to Anatidae species was 2,852.5 from 2005 to 2008 in Lake Paldang. The number of Anatidae reached 97.4% of the total number of individual birds. For evaluating the loading amounts of N and P by waterfowl to Lake Paldang, the feces dry weight (g/day) of each Anatidae species was estimated by multiplying the body weight of the each bird by 2.25% and assumed that N and P in feces contain 1.46% and 0.33%, respectively. We assigned probability 1/3 to the nutrient decomposition of the bird feces in water. The nitrogen loading by wintering waterfowl feces was 0.06 ton/year and the phosphorus loading was 0.001 ton/year. These amounts were 0.0002% of all N loadings and 0.0001% of all P loadings. Therefore the wintering waterfowl might have little impact on the water quality in terms of eutrophication in Lake Paldang.

• 한국환경보건학회지
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• 제38권5호
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• pp.424-430
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• 2012

Objective: The purpose of this study was to present the standard deviation of the elemental normalization of concentration of selected heavy metals in the surface sediment of Lake Paldang. Methods: Grain size dependency of selected heavy metal concentrations in the surface sediments of Lake Paldang was analyzed by the extrapolation method. The heavy metal concentrations were the sum of all fractions. Results: Cd and Cu showed an increase of the coefficient of determination($r^2$) in the fractional content of particle size, from <256 ${\mu}m$ to <20 ${\mu}m$, and a decrease from <20 ${\mu}m$ to <1 ${\mu}m$. The normalized concentration of Cd and Cu by extrapolation at 50% <20 ${\mu}m$ were 0.8 mg/kg, 37.0 mg/kg, 57.6 mg/kg and 201.7 mg/kg respectively. Conclusions: The normalized concentrations in the sediment of Lake Paldang are 1.5-2.0 times higher than mean average concentration. We concluded that in interpretation of heavy metal concentration in the sediment of Lake Paldang, normalization of grain size dependency should be considered.

• 한국물환경학회지
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• 제25권2호
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• pp.295-305
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• 2009

The purpose of this study was to understand of water quality characteristics of lake Paldang, especially at a certain representative site, right in front of Paldang dam ($P_2$ site) and to propose the directions of water quality management of lake Paldang. Water characteristics at $P_2$ site was investigated by principle components analysis and the Pearson correlation coefficient analysis. Also, seasonality was identified by the Kruskal-Wallis test and long term trend of nutrients and chlorophyll-a was analyzed by seasonal decomposition method at lake Paldang statistically. The primary factor affecting on water quality at $P_2$ site was identified as nutrients, while physical parameters, such as rainfall and inflow rate were also important factors. At the result of linear regression analysis particulate organic phosphorus (POP) vs total phosphorus (TP) showed very high correlation of 0.78. TP loading was increased annually from 1995 to 2006. Chlorophyll-a and nutrients show seasonality at $P_2$ site. Long term trend of Chlorophyll-a was increased by increase of TP at lake Paldang.

• 대한환경공학회지
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• 제36권5호
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• pp.367-377
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• 2014

국내 최대 상수원인 팔당호는 하천형 호소로 분류되며, 팔당호 수질은 외부오염원의 영향이 크다. 이에 본 연구에서는 팔당호 상류지역의 오염원 분포와 오염물질 유출특성을 분석하여 BOD와 TP 관리를 위한 중점관리 오염원을 선정하고자 하였다. 이를 위해 11개 단위유역에 대한 오염원별 발생부하량과 배출부하량을 조사하고, 74개 소하천의 수질 유량 측정결과를 이용하여 유달부하량과 유역면적당 유달부하 밀도를 분석하였다. 오염원별 BOD, TP 발생부하량과 배출부하량, 유달부하량을 분석한 결과, BOD 발생부하량은 축산계가 66.0%로 가장 높은 비율을 차지하였고, BOD 배출부하량은 생활계가 42.7%를 차지하였으며, BOD 유달부하량은 축산계와 생활계가 각각 36.4%, 34.3%를 차지하는 것으로 나타났다. TP 발생부하량과 배출부하량, 유달부하량 모두 축산계에서 가장 높은 비율을 차지하였으며, 각각 82.5%, 44.4%, 46.7%로 나타났다. 또한 BOD 유달부하밀도는 인구밀도가 높은 경안천 유역이 $14.6kg/km^2/d$으로 가장 높았고, TP 유달부하밀도는 가축사육두수가 많은 청미천 유역이 $1.23kg/km^2/d$이 가장 높게 나타났다. 이러한 연구결과를 통해 팔당호 수질개선을 위해서는 생활오수와 가축분뇨를 중심으로 오염원관리가 필요하며 경안천 유역은 생활오수에 대한 관리가 필요하고 남한강 유역, 특히 청미천 유역은 가축분뇨에 대한 관리가 필요한 것으로 판단되었다.

• 한국물환경학회지
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• 제29권1호
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• pp.19-28
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• 2013

Artificial neural networks were used for time series modelling of algal dynamics of whole year and by season at the Paldang dam station (confluence area). The modelling was based on comprehensive weekly water quality data from 1997 to 2004 at the Paldang dam station. The results of validation of seasonal models showed that the timing and magnitude of the observed chlorophyll a concentration was predicted better, compared with the ANN model for whole year. Internal weightings of the inputs in trained neural networks were obtained by sensitivity analysis for identification of the primary driving mechanisms in the system dynamics. pH, COD, TP determined most the dynamics of chlorophyll a, although these inputs were not the real driving variable for algal growth. Short-term prediction models that perform one or two weeks ahead predictions of chlorophyll a concentration were designed for the application of Harmful Algal Alert System in Lake Paldang. Short-term-ahead ANN models showed the possibilities of application of Harmful Algal Alert System after increasing ANN model's performance.

• 한국물환경학회지
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• 제29권1호
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• pp.7-18
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• 2013

We compared the structure of fish community and condition of major fish species in Lake Chungpyung and Lake Paldang, which are relatively shallow, meso-eutrophic, cascading dam reservoirs on the North Han River. Two lakes have wide littoral zone in the lakeside providing similarly good habitat for fishes, whereas fishery and water recreational activities such as motorboating, water skiing are allowed in Lake Chungpyung but are prohibited in Lake Paldang. The average lengths of large size fishes in Lake Chungpyung are shorter than those of same species in Lake Paldang, resulting in the slight distortion of generation distribution of those species in Lake Chungpyung, possibly owing to the active fishery such as fixed shore net fishing, gill net fishing and angling. Meanwhile the condition of fishes represented by the length-weight relationship of fish species did not show the significant differences between two lakes and showed normal condition. To evaluate the impact of physical disturbance such as loud noise and turbulent wave from water recreational activities to fishes precisely, further studies including physiological responses to stress an spawing activity should be needed.